This invention relates generally to electric ceiling fans employed to circulate air within the confines of various spaces. More particularly, it relates to ceiling fans that are operable in remote locations owing to their being powered by a portable, rechargeable energy source.
Ceiling fans have been known since electrical energy became available on a widespread basis to various locations at which people regularly frequent, including but not limited to offices, homes, warehouses, and virtually any other enclosed structure. Ceiling fans are currently used extensively to enhance personal comfort by providing air flow in areas that otherwise containing stagnant air. In enclosed areas they are especially useful in circulating and mixing hot air with cooler air to remove thermal gradients that tend to make rooms uncomfortable for inhabitation. During cold periods when heating is employed, ceiling mounted fans preferably circulate hot air from an upper portion of an enclosed space downwardly, and where cooling is employed as in summer months ceiling fans preferably circulate cool air upward. However, while ceiling fans have been found especially useful in providing enhanced comfort to spaces occupied by people for several decades, their use heretofore has been restricted to areas or rooms which are equipped with sufficient electrical wiring in order to provide electrical energy for the motive means used to drive the fan blades. Stated another way, locations having no electricity available must employ ventilation means other than electrical appliances, including ceiling fans.
The prior art provides ceiling fans of various designs. However, the primary requisites of the most commercially successful ceiling fans have been that the ceiling fan must include as a part of its construction a plurality of blades which are rotatably mounted to a fixture of sorts, which frequently comprises the armature of an electrical motor; a motive means for causing the rotation of said fixture, which typically comprises an electrical motor; and a source of energy by which the motive means is set into motion. Additionally, it is often desirable to arrange a cooperating collection of such elements in an aesthetically appealing configuration so as to add beauty to the decor of the room in which the fan as a whole is to be located. Most commercially-available ceiling fans intended for use within a house environment fall within this category. Exemplary of this class of ceiling fan are those sold under the Hometrends.TM. trademark, including but not limited to the models known as "Rainbow", "Polished Brass" and "White" marketed by Wal-Mart Stores, Inc. of Bentonville, Ark. 72716 and having various blade diameters in the range of about 30 inches to 52 inches. Another typical ceiling fan are those sold under the House Beautiful.TM. trademark of the Hearst Corporation and also marketed by Wal-Mart Stores, Inc. Yet another typical ceiling fan is the "New Orleans Classic".TM. model of Litex Industries, Inc. of 2002 Avenue R, Grand Prarie, Tex. 75050.
In the design of the aforesaid ceiling fans, which are intended to be illustrative of those generally available in the stream of commerce and not be delimitive thereof in any way, there is typically provided a mounting means for securing the fan assembly as a whole to a ceiling, an extension bar disposed between the mounting means and a motor assembly, and a motor assembly which houses the drive motor. Generally, the armature of the drive motor is circular in dimension and has a plurality of fan blades connected to it or in mechanical contact therewith such that energization of the drive motor causes rotation of the fan blades. In general, the motor assembly which houses the motor is cylindrically shaped having a length dimension which is less than the diameter dimension. The housing is equipped with holes which serve as passageways through which air may pass by virtue of the blades rotation. In this manner, the motor is kept cool.
Generally speaking, the ceiling fans of the prior art are operated using house current which is typically delivered at a potential of 110 volts at 60 Hz. Accordingly, the motors employed as drive means are typically of the AC synchronous type. Ceiling fans exemplary in the prior art include those described in U.S. Pat. Nos. 4,689,533; 4,721,480; 4,782,213; 4,796,166; 4,810,207; 4,828,115; 4,841,188; 4,862,581; 4,900,236; 4,934,126; 5,054,376; 5,069,601; 5,072,341; 5,154,579; 5,222,864; 5,256,037; 5,333,235; 5,421,701; 5,511,943; 5,524,450; 5,558,501; 5,562,421; 5,658,129; 5,725,190; and 5,797,721, the entire contents of each of these prior-art patents being herein incorporated by reference thereto. These prior art fans generally comprise a rotatable assembly to which the fan blades are attached and a stationary assembly in or capable of being placed in connection with a suspension means. The rotary assembly comprises the rotor and the stationary assembly the stator, located coaxially inside the rotor, of an electric motor, having a common centerline. The rotatable assembly is mounted rotatably relative to the stationary assembly by means of a tubular member extending coaxially with the common centerline and a shaft located therewithin. Two bearings located at a distance one above the other are installed between the shaft and the tubular member. One of the bearings is a roller bearing. In this arrangement, the shaft is mounted in the tubular member by means of two rolling bearings, the tubular member being integral with a bottom or end dish belonging to the rotatable assembly, to which the fan blades are attached and the shaft is connected at the top thereof to the suspension means.